Evaluate the definite integral. $\int^3_{5}2\,dx = $
Answer: First, use the power rule: $\int^3_{5}2\,dx ~=~2x\Bigg|^3_{5}$ Second, plug in the limits of integration and simplify: $[2\cdot3]-[2\cdot{5}] = 6-10 = -4$. The answer: $\int^3_{5}2\,dx ~=~ -4$